This relates generally to video resizing.
In video resizing, the size of the depicted frame is changed from its original format. For example, the aspect ratio of width to height may be changed. One common resizing changes the aspect ratio from a 4:3 ratio to a 16:9 ratio.
Sometimes, video resizing causes video jitter or slide. In video jitter or slide as a result of resizing, one or more frames may not be aligned with previous or subsequent frames making it appear that depicted objects are moving. This can create a blurred motion effect for objects that, in fact, are not moving from one frame to the next.